The objectives of the proposed research are to: 1) isolate hypertrehalosemic neurohormone (HTH) from the nervous system of Blaberus discoidalis cockroaches; and 2) to characterize the primary structure of the isolated neuropeptide. HTH increases hemolymph trehalose concentrations and is stored and released from the corpora cardiaca (CC). HTH is extracted from whole heads of B. discoidalis with acidic organic solvent followed by solid phase extraction and final purification on reverse phase HPLC. The homogenous peptide will be structurally analyzed by controlled degradation by exopeptitdases of Edman degradation followed by DABS-CL HPLC amino acid analysis. The proposed research is a prerequisite for further definitive study of HTH neuroendocrinology. Adequate amounts of pure HTH must be available for the development of antibodies, radioimmunoassays, immunohistochemical techniques, definitive pharmacological studies on neurosecretion, analog development, and mode of action studies. The results of this research will provide a simple model for the study of basic neuroendocrine mechanisms not possible in the more complicated vertebrate nervous system. This system will provide information, not only on fundamental processes of neurosecretion, but may also lead to future ways by which neurosecretion or its resultant hormones may be manipulated for insect control.